Study And Simulation On The Model Machine Of Integrated Rotate Cyclone Separators

An integrated rotate cyclone separator, short for an integrated machine, is a new type ofgas-solid separation device, mainly consisting of a centrifugal impeller and a separationmuff. With the centrifugal impeller rotating, the integrated machine will do work to the air,and separate the particles with huge centrifugal forces, so that the integrated machine canhave two functions: efficient separation and gas transportation at the same time. However,the geometry structure of new machine is with a lot of structural parameters so complex,then the theory and design method are not applicable to design the integrated machine. Abetter theory should be established by a lot experiments and structural developments. Inorder to avoid blind experiments as well as reduce the experimental workload, CFD wasused to study the gas-solid flow field in the model machine, including flow field s andseparation performance. Moreover, the simulations of separation muff were done to find therelationship of pressure drop, operating parameters and structural parameters. Main tasksand results are as follows.(1) Through the comparison of different calculation scheme s, we determined simulationmethods suitable for the flow field in the integrated machine: sliding plane for rotor/statorinterface processing method, Reynolds Stress Model for viscous model, QUICK scheme fordiscretization of advection terms, PRESTO! scheme for discretization of pressure gradient.(2) Through the study and simulation on the gas flow in the model machine, we found thataxial vortex exists in the vertical blade part of centrifugal impeller, and reduces theefficiency and total pressure of the impeller. The flow field in the separation muff issymmetrical and the main body is double vortex flow, and the inner is upward quasi-forcedvortex. These benefit to swing the particles to the wall. The outer is downward quasi-freevortex, and it takes the particles to the ash hopper to be captured. Besides, the pressure dropof separation muff is so large and the total pressure of centrifugal impeller is so small, thatthe model machine is unable to realize the function of gas transportation, therefore structural developments are needed.(3) Discrete Random Walk model was used to simulate the solid phase in the modelmachine, and the results demonstrate that the integrated rotate cyclone separator has goodseparation performance for ultrafine particles.(4) Through the study and simulation on the separation muff, we found that the relationshipof pressure drop Δp2and tangential velocity vtas well as axial velocity vain the inlet ofseparation muff can be expressed as p2986v2v22.6t31.539a. Otherwise, the pressuredrop Δp2of separation muff and its internal tangential velocity decrease as the diameter ofgas exit tube increases.